hotchkiss



2 Shestsr Sheet 1.

B. B. HOTCHKISS. Combined Ti me'and Percussion Fuse fbr Explosive Shells. No. 72,494;

Paten ted Dec. 24, 1867.

B. B. HQTCHKISS.

Combined Time and Percussion Fuse for Explosive Shells.

2 Sheets-Sheet 2,

No. 72,494. Patented Deci 24, I867.

guitar .gtstes gamut B. B. HOTCHK ISS, or NEW YORK, N. Y.

. Letters PatentNo. 72,494, dated December 24, i

IMPROVEMENT IN commune TIME AlllD Percussion-Puss roe sxrLoswr sums.

are -5:tnrte mum in it lies: Enters not: an milling put at it: sums.

TO ALL WHOM IT MAY CONCERN:

i Be it known-that I,B. B. Horcmnss, of the city, county, and State of New York; have invented certain new and useful Improvements in Fuses for Explosive Projectiles; and I do hereby declare that the foll'owingis a full and exact description thereof, prepared with a'view to the obtaining of Letters Patent therefor.

I will first explain some of the previously-known devices which are employed therein.

A fuse in common use, known as the Barman fuse, encloses the slow-burning material in the form of anearly complete ring. The ring is interrupted at one point by a firm metallic partition, and close to one side of this partition the fire is allowed to communicate with the explosive contents of the projectile. The artillerist. is provided with a gouge or other convenient tool, by which he cancut open the front face of the'metal at any point in the ring, and thus expose the slow-burning material to be ignited at thatpoint, while it is protected at all other points; The fire to ignite the fuse at such point is sometimes derived from the propelling-charge, and sometimes from other sources. When the fuse-.is 'cut open so as to expose the slow-burning material at a point directly over where it communicates with the interior of the shell, the contents of the shell will be ignited very soon after the gun is fired. But when the artillerist makes the'cut at a point considerably removed from where the slow-burning material communicates'with the interior of the shell, the time of the explosion is correspondingly delayed, because there is a longer train of slow-burning material to be first consumed.

My invention is based on the above-described invention by Qaptain Barman, aml ,ou thenimmmements which 'have'been madeby oth ers in connection th erewith. I I

My invention is intended more particularly for the elongated shells usedin rifled ordnance. I shall represent it as applied to a shell of the kind manufactured by me and my associates, kubwn as Hotchkiss shell.

To enable others skilled in the art to successfully make and use myinv ention, I will proceed to describe its construction and operation in the'best manner known to me, by the aid of the accompanying drawings, which form a part of this specification, and of the letters of reference marked thereon;

Theindividual parts of the combined apparatus, which I shall so represent and describe, comprise the Borman fuse and other devices previously invented by various parties, some of which are patented. They comprise some features already previously patented by myself. I believe the details represented to be preferable to any others which are now knownand can be made available to perform corresponding functions in this invention;

but I do not mean to confiuemy present invention to all of these details,'or to its application to the Hotelikiss shell. I

Figures 1 and-2 are side views of the front end of a rifled-cannon shell with my improvement. Fig. 1 shows the parts in the condition adapted for handling and transportation. "Fig. 2 shows the parts in the condition for use, a cap which protects a certain sensitive part having been removed- Y Figures 1" and 2 are end views corresponding, respectively, tofig. 1 and fig.-2.

Figure 8 is a side view of the central portion of my fuse detached from the shell. This part is adapted to be readily inserted and removed.

Figure 4 is a section on the line S S in fig. 3. A Figure 5 is a longitudinal section of the front portiouof the-projectile or shell as it appears when prepared to receive the fuse, but beforeany portion .of the fuse has been inserted.

Figure 6 is a similar section,- with all parts of the fuse iii-place in the shell. In figs. 1, 1,3, 4, and 6, the front cap is represented in place, protecting the front end of the centralportion of my fuse. Under-{this protection is a very sensitive material adapted to ignite, by theslightest'flame which maybe thrown upon it, while' the shell is being driven forward in the gun.

Figure 7 is a section corresponding to fig. 6, but with-thiscap removed, as to ex posethe aforesaid sensitive material, and thus aid in adapting the shell for use.

Figure Sis a similar section, showing the sensi,tive material in a state of ignition, its presence being indicated only byradial lines. The shell is driven forward in the gun in this condition, and the flame produced by the burning of this material envelopes the front of the shell and ignites the point in the Borinan which has been cut open.

ring of propersizc, with special reference to its use in such a situation.

Figure 9 is a similar section, showing the projectile at a late period in its flight, just asthe Barman is com! municating fire to the interior of the shell: v

Figure 10 is}: face view of my Barman before it is forced into the shell.

Figure 11 is a section of the same on the line S S, in fig. 10.

Figure 12 is a rear view of the same.

Figure 13 is a side view, and I p Figure 14' an edge view of a wrench adapted to operate the cap, and also the entire central portion of my fuse. 4

Similar letters of reference indicate like parts in all the figures.

Fig. 5. A is the main body of the -shell, formed of cast iron, and B is the interior cavity. The ordinary fuse-hole is indicated bya It is of the usual size, and is tapped in the ordinary manner, the thread of the tap corresponding with that of ordinary flises, so that on any emergency, when my fuse is damaged, or for any reason/cannot be used, ordinary fuses'may be used in the shell and produce their usual effects. I

On the frontend of my shell, and conoentriccwith the fuse-hole a, I cut-an annular recess, asindicated by a'a I make the bottom of this recess a little wider than the top, using for the purpose-a tool speciallyadapted,

therefor, and which will probably be made the subject of another patent at an earlyday. It is not necessary todescribe here the patentablemeans whereby I produce this recess, inasmuch 'as any good mechanic will be able' to accomplish the same end, though-more slowly, by the aid of the tools-in common use in machine-shops. This circular recess a is intended to receiveand retain the Barman fuse, which I construct in the-form of .a

" Figs. 6, 7, 8, 9,10, 11, and 12 G G c is the main body, and G the partialring, which form sthe rear faceof the Barman. Both the parts, 0, &c., and vG, are made of soft metal, the same as-is usually employed in Borman fuses. D is the slow-composition, which is enclosed in the fuse between the parts C-and G. The junction of Q and C is effected by pressing the parts very tightly together, after the slow-composition D is in place. I make the fuseof such size that it enters the narrow front of the circular recess'a without much dilficult y, and I afterwardssubmit'it touch a pressure as shall force it firmly down on the bottom-of the recess a', and spread it so as to occupy the whole of-the -Zwid'ened interior of the said recess. The act. of thus pressing it home widens the partsO, .6, and D, so that the relations ofthe parts are not changed.

I make the partial ring or back-piece 0 about ue-eighth of an inch shorter than the cavity in the main part 0, which it is designed to cover. When- I insert the-slowcompositiou D and the back-piece G into the main part 0 of my Borman, I maintain an empty space between one end off} and the firm partition 0, by-having.

. previously introduced the end of a. suitable tool-or former, not represented,w hich entirely fills the cavity in'the maintpart G, at that point. It follows that after the operation of charging my Barman with slow-composition,

and of covering the'same with the back-piece Q is completed, the withdrawal ofthe tool referred to'leavs .an. empty space at this point.- This space I subsequently .filbwith quick-powder, d, and to maintain the latter in its place, I apply a little shellac, and finally cover the base or back of the fuse at this point with asmall piece of tin-foil. This tin-foil is indicated by E, but its thickness in the drawing is greatlymagnified. The quickpowder 11 thus enclosed explodes with considerable force whenthe fire arrives at thatpoint, and is able to throw the flame to a considefa'bledistance, either through a direct or tortuous passage, into the shell, so as to explode its contents the moment the fire has arrived at that point in traversing the slow-burningmaterial.

Figs. 5, 6, 7, 8, and 9. G is a hole, some one-fourth of an inch=in diameter, drilled in..th e bottom of the circular groove a, in a line parallel, or nearly so, with the axis of the shell. This hole is .tzol'atracted before it reaches theinterior B of the shell, but is prolonged by the small hole'g, which is only about, one-sixteenth of an inch indiameter. I fill the small hole 9 with beeswax or with'qu'ick-powder, satnrated witb. shellac or collodion, so as to cause it to adhere to the metal of the shell A. I then fill the large hole or cavity G with quickpowder, and afterwards press down the Borman thereon, as before described. In filling the hole G, I take care" e' rainsso coarse that evenin case the wax or other stopping. should become displaced and entirely removed from the small hole 9, the grains of powder cannot pass through, by reason of theirsize. I canvfill the cavity G with -a single grain of quick-powder, of the characterrecently introduced, and known as Doremuss.

When I force the Barman into theshell, I take care ,to have"the cavity G well filled with the quick-powder in coarse grains, as above described, and to place the Barman in such a position that the7tin-foil E shallcome" directly against the powder in the cavity G. When the'slow -composition D is burned to the right point, the

quick-powder ghwhich is enclosed in the Barman, explodes, and, bursting through'theti-n foil E, coinmunicatesv 'fireto the onion-powder in tlicavityGi"The"lfiiter,"liy ns-explosion;-remms 111w stoppingifi th -snratr sta rsg, and throws fire into the shell, causing the ignition of the'contents, and a consequent eiplosion', or the emis- I sion of fire or noxions fumes, according as the cavity B is charged.

I esteem the powder d in my Borman suificient under allordinary circumstances to throw the fire through the passages G g, or through any other reasonable passages,wlthout the aid of the powder which I have described above as enclosed-in the cavity G. And, again, I consider the powder in the cavity G certain under all-ordinary circumstances to ignite from the slow-composition 'D, without the aid'of th-evqnick-powder d. Ican use-the powder d without the powder in the cavity G, or. the powder in the cavity G without the powder 11. I have experimented with my shell in both these conditions with complete success. But I consider the use'of both the powder d and the powder in the cavity G as tending to make the ignition of thematerial contained in the cavity B more infallihly certain. I

I employ in my mannfactory a suitable die-press, not represented, with which to force my Borman p r operly into the .circular recess a after the'pewder has been introduced in the cavity G, as ubovedescribed. The shells may be transported to the seat of war with the'cavity B empty, and with the hole a stopped by the insertion of a piece of wood or a quantity of paper, or the like, merely'to prevent the entrance of foreign substances into the cavity B. When it is desired to prepare a quantity of such shells for use, the temporary stopping in the hole a is removed, the cavity B is filled with powder, either alone or inconnectiori with balls, or it is filled with port-fire or other incendiary or offensive materials. v I

I will now describe the part of my fuse which I finally screw into the cavity a to complete my-fuse, it being understood that the same may be inserted in the first instance, so as to complete it before leaving the manufactory, if preferred, but such practice would be less safe.

Figs. 1, 2, 3, 4, 6, 7,8, and 9. H is a hollow casting or fuse-plug, of brass, provided with athread on its exterior, adapted to match the thread in the hole a, and with a flange on its front end, adapted to fit tightly down upon the shell by the aid of an ordinary washer of leather,'or the like, as represented. A hole, It, opens through its rear end, as represented. I is a plunger or striker, adapted to ignite the contents of the cavity B by the concussion on striking, in case the Borman has for any cause failed to act. My plunger I is miide in accordance with my patent, dated February 24, 1863, and is provided with a wire, 2', by which it is'secured in the hole It by the aid of the leaden plug J, in accordance with my patent dated June 17, 1862.

K is a front stopper, of brass, enlarged at its rear end and also at its front end, indicated respectively by K and K. This frontstopper K is provided with a thread on the enlarged part K, which fits very tightly in a corresponding thread on the interior of the front end of the casting H. A portion of this thread is allowed to appear beyond or in front of the casting H, where it performs a useful oflice in retaining the cover, cap, or

protection, which is provided with a corresponding female thread, and is put on and oh by turning it around in the manner which will be obvious. L is a'quantity of quick-burning material which is secured around the plug K. I prefer to apply this quick-burning material or quick-match by taking loose cotton-tricking, saturating it with a solution of gum-arabic, rolling .or rubbingit in meal-powder, and afterwards winding it around the plug K. This material is generally known in'the service as quick-match. But a quantity of gun-cotton, or of the slow or quick-material manufactured by pyrotechuists, or of a quantity of the materialfrom which gunpowder is manufactured, or of fulminate or other substance very liable to ignition, may be used at this point to form the sensitive material L; and any suitable means, such as dove-tailing, may be employed for holding it in place,

so as to endure the shocks incident to the handling and transportation of the shells, and to endure the shock which is experienced in the'diseharge of the gun". 4

M designates the froht cap, before described, which serves as a protection or covering for the sensitive. material L until it is required to be used. I make in both the cap M andfdse-plug H two recesses, as indicated, 7 which are adapted respectively to receive the prongs of a suitable wrench, by which I can turn them so as to introduce and remove them at pleasure. N, figs. 13 and 14, represents the wrench which 'I ordinarily employ. The part adapted to operate the cap M is smaller than the part adapted to operate the part H. l

The cavity B being charged, the casting'H is screwed tightly into the hole a, with its several iitta'chm nts and connections arranged as above describedyand the cap M-is screwed tightly down upon its front. The shell may now be transported safely to any reasonable distance; and the sensitive material L, and all the other delieate parts, are tolerably well protected from dampness, as'also from fire, abrasion, percussion, or other injury.

Before introducing the shellinto a caution for use, the proper point on the part of the Barman 0 must be cut open, asshown by c, and the protecting-cap M must be removed, so as to exposethe sensitive material L to any flame which shall circulate in the gun.. The shell thus prepared may be pushed home in the cannon in the ordinarymanner, and on the discharge some fire invariably rushes past the body of the shell and circulates in the interior of the gun in front. The material L is so favorably exposed to ignition from such source that I have rarely known it tofail to ignite, even if the shell A is adapted to fit the interior of the gun as tightly" as possible. But in order to insure such result, I prefer to provide longitudinal grooves, not represented, on the exterior of the shell A, which grooves allow the flame from the propelling-charge to pass the body of the shellAin large quantities. The contact of flame with any one point on the sensitive material L instantly ignites the whole of the said material, and its combustion envelopes the front of the projectile with-flame, so that the exposed point on the Bormau, which has been cut by the artillerist, is certain to be ignited, When the Barman is ignited, the slow-composition therein burns in both'directionsfrorn the exposed point, in the same manner as is ordinarily observed with the Barman fuse. When the proper time arrives, the fire reaches the quick-powder d, and by its aid, and of that in the cavity G, it projects the flame into theinterior cavity B and ignites its contents. In case, by any carelessness, or'by any imperfection inthe train of operations above described, the contents of the cavity are not ignited from the Borman' G D, &c., at the proper time, the percussion-striker I becomes important,-but otherwise it is of no efi'ect. The details of the construction and operation of the parts I i and their connections are described in my patents above referred to. But in the absence thereof the striker I may be briefly described as carrying a percussion-cap on a nipple on the front of the striker, a quantity of quick-powder in communication therewith in the interiorof the striker, and the wire a firmly embedded in the striker The rear end of the wire 2' is firmly held in the hole 71, by theaid of a taper ing;lead plug, J, until the discharge. of the cannon, and is then entirely released by the relative backward movement of both the striker I and the-plug J, induced by their inertia when the gun is discharged and the shell is projected forward. The lead plug, during the flight of the shell, remains loose among the powder or other contents of the cavity 13-, and the striker I, with its attached wire 1', remains loose in the cavity H and hole It, ready to be thrown forward with great violence and dash a percussion-cap against the rear end of the hard stopper Kwith explosive efi'ect when the shell strikes.

I will now describe a certain further peculiarity in the formation of my Barman; which, though not abso- Jutcly essential to the success of the other portions of my-invent ion, greatly contributes tothe value thereof.

I so cast the part 0 of my Barman, and so form the die by which it is forced 'intothe shell and imprinted,

that the face of the Bottom is elevated or protruded along the'centre line C; and I so form the interior cavity, in which the slow-composition -D is introduced, that the slow-composition shall protrude forward therein. In other words, the interior surface of the front of the part 0 of my Borman is parallel to the outer surface. This is one of the chief peculiarities of my Barman. I am aware that Bormanfuses have before been made with the front elevated along the centre line, or rather depressed along its outer and inner edges, so as to present precisely the same external appearance as this part 'of my fuse; but the interior of such Bormans was not correspondingly shaped. On the contrary, the central portion-of the front has always been thicker than i the sides. 'My Borman, by being thin at the centre, or rather bybeing uniformly thick across the whole front, provides eflicient protection for all parts of the slow-composition D, which is uncut, and yet allows thevcutting to be performed with greater facility than usual.

1' make sunk figures on my compressing-die, not represented which have the cfiect to produce correspondin raised figures on the front of my Borman, as represented. The slow-composition D correspondingly varies it"s contour in the interior, so as to well preserve a very nearly uniform thickness of the soft metal in front 'of it. When, from motives of economy or from any other reason, such as great confidence in the skill and coolness \of the artillerist, it is desired to dispense with the percussion-mechanism I i J I constructjthe parts 0 (l -C, 830.,

and the hole G- g, as above described, but dispense with the entire rear portionof 'the central part H aild' its contents. I use, in fact, only so much of the part H as is required totconne ct-the stopperJK and the cap M properly to each other and to the shell A. In such case I can make the part K and the'part H in a single piece. I have made such very successfully of soft metal; i p

I employ soft cement, when necessary as a safeguard against the entrance of moisture along the threads of the screw which connect the cap M to the swell K. The best mode of applying such is to wind a well-wnxed shoe-thread around K before'the cap M is screwed down, the wax being the pitchy compound usually'employod by 'shoemakers. Screwing the cap M tightly down upon such thread, I have made the joint so tight that a lot of such fuses which were thrown in a bucket of water on "Saturday, exhibited no deterioration when they were unscrewed and exposed to a slight flame on Monday. 2 a v Having now fully described my invention, what-I claim'as new therein, and desire to secure by these Letters Patent, (case A,) is as follows 1. I claim the employment, in an explosive projectile, of a quantity of quick-burning material, L, perm'anently attached and protruded beyond the front, and directly exposed to the contact of home on all sides, in combination with the surrounding Bor'man G, substantially as and for the purpose herein described. i

f 2. I claim the magazine G of quick-powder, arranged in direct contact with the Borman, and adapted to be ignited at the proper time thereby,-and to increase the force with which flame is thrown into the shell, snbstantiallyin the manner herein described. v

3. I claim, in the cavity magazine G, arranged as 'represented, 'the' use of powder in one or' more large grains, in combination with the contraction g, smaller than said grains and arranged to ,gperate therewith and retain the powder but discharge the flame therefrom, substantially in the manner and for the purpose herein set forth. V. 1

B. B. HOTGHKISS. Witnesses:

Tnoms D..Srsrso1r, D. W. Srsrson. 

